Portable electronic devices, such as computers, music players, phones or other electronic devices may receive power from an external power supply. Not all power supplies are compatible with every electronic device. A portable electronic device can have a power draw, for example the power draw of a notebook computer maybe, such as 60 watts. A power supply should be able to supply at least the maximum power draw of the portable electronic device or the portable electronic device may not operate or may have to disable some features.